1. Field of the Invention
The present invention relates to a dynamic reconfigurable circuit in which time division multiple processing is possible.
2. Description of the Related Art
The present invention relates to a reconfigurable circuit constituted by a network connecting a processor element and a processor element which process data. The reconfigurable circuit executes various kinds of functions at the speed equivalent to an ASIC by rewriting the configuration data which defines the operation of a circuit in terms of software. Therefore, various kinds of applications (tasks) can be executed in the same reconfigurable circuit. However, with the progress of circuit technology, the scale of circuits on which tasks can be loaded has increased along with the upsizing of a reconfigurable circuit. Under such circumstances, it is considered to be required that a plurality of tasks can be simultaneously executed in one reconfigurable circuit.
The method of executing a plurality of tasks in a conventional reconfigurable circuit is divided into two types. One is the method (space parallelism) in which a circuit is spatially divided, and a task is allocated to each divided space (for example, Patent Document 1), and the other is the method (time parallelism) in which a configuration is switched to time division to execute a different kind of task.
In the latter method of switching the configuration in terms of time, after a task is processed in the configuration corresponding to the task, internal data is once spilled out or retracted to another place, and then said configuration is switched to a configuration corresponding to another task. In order to implement the switching more efficiently, the switching of tasks is realized by implementing said switching partially.
In the method in which the configuration is divided in terms of space to execute a plurality of tasks, hardware resources are required according to the number of tasks to be processed to keep a high level of processing performance, so that the scale of the circuit becomes larger.
On the other hand, in the method in which the configuration is switched to perform a plurality of processes in a time division way, time overheads are generated due to the interruption of the pipeline processing occurring when the configuration is switched. Furthermore, buffer processing of input/output data for retract processing is also required, so that the processing time from data input to data output (latency) increases. Furthermore, since the processing is performed in a time division method, the time required to process a task having the same processing amount becomes longer according to the number of tasks depending on the case where a single task is processed or the case where a plurality of tasks are processed.
[Patent document] (Jpn. unexamined patent publication) No. 2000-311156